Smoking from the turbo

[first230sl]

Hey there. I typically run at 1500RPM (8V71TI's), but once every couple runs I take it up to WOT for about 10 minutes to clean things out. When I do this, I go to the engine rooms to look around and take temps with the I/R thermometer.

Last time I did this, all else was well, but I noticed that one of the turbos (STBD, outside) had smoke coming from it. Not profuse, but quite noticable. I could not tell exactly where it was coming from because of the thermal blanket it was wrapped in. Back at 1500 RPM there was, and is, no smoke.

I don't know if it is oil leaking & buring, or exhaust leaking or the blanket getting too hot or ???

Obviously I have to take the blanket off and take a closer look, but I thought I'd ask here first if there is anything I should be looking for.

Is it OK to run the engine with the turbo blanket off?

Any other advice?

Thanks so much.

Murray

 

[Liquid Asset]

It sounds to me like a leak, but I think you need to take the blanket off and get a closer look. I bet you will see it imedietly after removing the blanket

 

[Genesis]

Either an exhaust leak or you have an oil leak into the blanket.

The latter is EXTREMELY dangerous - if the blanket is oil soaked fix the leak and change the blanket out immediately - it can catch fire under there, and if it does, it will be extremely difficult to put it out.

 

[Eufaula]

At times running the 871T'S COLD it will "soup up" then when you open her up it will smoke around the turbo, but this could be only momentarily defense on how much is in the manifold.

OR, it could be the gks. on the exh.gas side of the turbo. The ss/clamp holding the exh. gas. Should you remove the lagging of the turbo and see blk. oil mark then I would say for sure it is souping up. A common 71 problem. And, I could go on and on with cause such as too large injectors for the load etc. but..
James.

 

[solanderi]

FWIW,

I over oiled one of my four Air Seps (rookie mistake), and had air sep oil hit the blankets and give off a few puffs of smoke. Not fun to witness, but there you have it.....smoke from the blankets. Obviously a potentially hazardous problem as pointed out above. Good luck !

 

[SKYCHENEY]

I had the same problem last year on port 6v92. Pulled the blanket, found oil leak on input side. Tightened it and cleaned the whole area up with brake cleaner. It still smoked for a while until all the residual oil burnt off. After that is was fine.

 

[Genesis]

Turbo blankets are about $100 each. Cheap enough to just replace them if there is oil on the insulation.... I would not take the risk of a fire in one.

 

[first230sl]

Thanks to all.

I assume it is safe to run the engine at high RPM under load with the blanket off (as long as it isn't touching anything - especially me)?

Let me know if that is false.

Thanks.

 

[Genesis]

False.

A turbo under full load runs VERY hot (can be up to 1000F!) and will ignite things that can burn that are not in direct contact. DO NOT RUN THE ENGINE WITH THE BLANKETS OFF!

The blankets are there to prevent fires and melted things in the vicinity, and MUST be on the turbo when the engine is running.

The only exception is for short periods of time on a cold engine at idle (e.g. troubleshooting exhaust leaks)

 

[first230sl]

OK - thanks. Hopefully the problem will be apparent without having to run the engine. I'll take a peek!

Take care - Murray

False.

A turbo under full load runs VERY hot (can be up to 1000F!) and will ignite things that can burn that are not in direct contact. DO NOT RUN THE ENGINE WITH THE BLANKETS OFF!

The blankets are there to prevent fires and melted things in the vicinity, and MUST be on the turbo when the engine is running.

The only exception is for short periods of time on a cold engine at idle (e.g. troubleshooting exhaust leaks)

 

[seacolt]

I had the same problem. Ironically, 871TI same (starboard) outboard side as yours. Turned out to be a pinhole in the oil return line, causing smoke at high RPM.

 

[Genesis]

A trick for finding exhaust leaks...

On a DEAD COLD engine, remove blanket. Start engine. Immediately spray the turbo liberally with 409. Look for BUBBLES. If you see them, there's your leak.

For oil leaks check the return line - feel around it. If its oily, its leaking. Replace the hose portion if you suspect the connection hose between the block and turbo.

Supply oil leaks are usually obvious on a cold start, as the oil pressure is very high at that time.